As with most cases of governmental excess in the shadow world of intelligence, the attitude goes a long way back in American history. It can be traced at least to the Alien and Sedition Acts under John Adams, and Abraham Lincoln's suppression of the habeas corpus protection that trampled civil liberties in the young nation and then in the Civil War.
Later, there was Lyndon Johnson's defense of expanding the American military role in Vietnam based on the supposedly superior intelligence he possessed, and then Richard Nixon's arrogant contention that if the president of the United States did something, that automatically made it not only right but legal.
More recently, George W. Bush justified his invasion of Iraq in 2003 based on faulty or even nonexistent government intelligence that Saddam Hussein had weapons of mass destruction poised to assault the West. His legal advisers further argued that Mr. Bush could deal with suspected terrorists and other captives as he chose, flaunting the Geneva Conventions on conduct in war and their prohibition of torture.
Indeed, the concept of the "unitary executive" espoused by a Justice Department lawyer named John Yoo argued that a president of the United States in wartime could basically do whatever he wanted under Article II of the Constitution. Mr. Yoo made the case, with some success, that the president's role as commander-in-chief of the armed forces trumped Congress' specific mandate to declare war.
President Barack Obama, campaigning in 2008 to end the American engagement in Iraq in what he called a "dumb war," has sought to wind down the U.S. combat role there and in Afghanistan, but has fallen far short of that objective. And while largely abandoning Mr. Bush's rhetoric about a "war on terror," he has not departed materially from its pursuit.
On the basic question of the apparent wide intelligence net cast by the National Security Agency, the Central Intelligence Agency and even the Federal Bureau of Investigation against the real terrorist threat, public opinion still seems to stand behind this or any president.
The contentious aspect of the governmental snooping, whether by the NSA or domestically the Internal Revenue Service, is its dragnet scope and what can be argued as excessive secrecy, in the NSA's case all in the name of keeping real or potential enemies in the dark. It's all well and good for Mr. Obama and other officials to say the content of their wired interceptions is not the target and is not listened in on. The Big Brother concern remains ingrained in a society conditioned by fear-inducing spy fiction and movie thrillers.
In all this, the nation's core commitment from the start to civil liberties, particularly freedom of religion and speech, was a direct outgrowth of the British monarchical suppressions of the American colonies. It has continued through the years amid a variety of threats.
Not surprisingly, a debate has already sprung up on whether the admitted leaker of the huge NSA electronic surveillance, technology specialist Edward Snowden, is a villain or a hero, and whether he should be hunted down as a criminal by American law enforcement agents or put on an American Civil Liberties Union pedestal.
Mr. Obama himself has deplored the leak as undermining the federal government's basic obligation to take all means necessary to uncover and prevent any further acts of terrorism on Americans, from whatever source. But as a declared defender of civil liberties who already is in bad odor with liberals in his party, he risks further political erosion if he comes off as a hard-knuckle enforcer. It's a balancing act between his responsibility as the nation's chief law enforcement officer and his political conscience that he can't sidestep.
Jules Witcover is a former longtime writer for the Balimore Sun. His latest book is "Joe Biden: A Life of Trial and Redemption" (William Morrow). You can respond to this column at email@example.com.